This is a bit of an oversimplification. Just because two things happen around the same time does not necessarily indicate correlation (or causality) — particularly when there are innumerable other factors in play. In addition, besides the fact that all social progress comes with backlash, we very clearly and demonstrably have younger generations of men who do not subscribe to some of the more offensive parts of so-called "traditional masculinity." In other words, deprogramming masculinity from the 1950s is not only working, it is beneficial for men most of all. We don’t need less of that, we need to go all the way to where men are actually allowed to have the full range of human emotions.
"Some men are able to reject restrictive, negative social pressures related to masculinity, but many embrace these pressures and rules, as well as the version of manhood they represent. Young men in all three countries overwhelmingly reject notions of manhood that imply that men are superior to women or that men should not care for children. However, they show strong support for toughness and the repression of emotions. Indeed, while men in the three countries have come a long way toward accepting equality between women and men, they still have a long way to go to break free of norms that hold them in emotionally straightjacketed forms of manhood."
Incels have been told by patriarchy that men are entitled to women — that this is what women exist for — and they aren’t getting “their fare share” which is what they are so mad about. If they were actually a byproduct of a “soft” version of masculinity, they would have a lot more empathy, and not look at women as essentially living sex dolls that they ought to have access to by right.
Here’s my take from several years ago about what is really going on with incels.